Helio plate

[Catbird]

Hello, this plate is located on the edge of the front left door structure of the Italian Helio and refers to the last revision made in Italy. Can you tell me how to read? 391 is the model?

Guglielmo

[Jason Stephens]

Looks like a data plate the Italian government added.  The typical data plate location is low on the tail below the stabilator.  I would look to see if the original data plate from Helio is still on the aircraft.